Some engines, such as diesel engines, rely on compression ignition by compressing air and injecting fuel into the compressed air to substantially immediately ignite the fuel without requiring a spark plug. Compression ignition engines may include a common rail fuel injection system, directing pressurized fuel to individual fuel injectors for injection into the combustion chamber. Fuel injection systems may utilize a system that selectively increases the pressure at which fuel is injected into the combustion chamber. Such a system may include a piston disposed within a chamber for increasing the pressure of fuel. The chamber may be fluidly connected to the nozzle of the fuel injector. The piston may be selectively displaced to force an additional volume of fuel into the fuel injector nozzle, thereby increasing the pressure of fuel injected into the combustion chamber. Typically, the piston is displaced to increase fuel pressure via a solenoid assembly and returned to its initial position via a spring.
U.S. Pat. No. 6,805,101 B2 (the '101 patent), issued to Magel, describes a piston for selectively increasing a pressure of a fuel injection system. The piston divides a housing into two separate chambers. The piston selectively displaces within the housing to increase the pressure of fuel within one of the chambers. The system of the '101 patent includes a restoring spring that returns the piston to an initial position.
Although the fuel injection system of the '101 patent may provide a method for providing fuel to a combustion chamber at an increased pressure, it requires additional components such as, for example, the restoring spring that may increase manufacturing costs. Also, these additional components may experience wear due to high pressures associated with increasing the fuel pressure.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above.